Wadden Sea (Denmark)

Abstract

The Danish part of the Wadden Sea comprises 1,500 km2, and makes up about one tenth of the whole Wadden Sea area. In contrast to the other parts of the Wadden Sea the water quality in the Danish section is not influenced by large rivers, but mostly inputs from the North Sea. During the period 1990–2010 nitrogen in the water body has been nearly halved. The increase in the number of houting, an endemic fish species, indicates it may now be secure due to intensive river restoration. Breeding birds are numerous, but the populations of many species have decreased recently. Millions of water birds stay during spring and autumn, and the site is of international importance to 20 species. The harbour seal is the most numerous of the sea mammals, and the small population of grey seal is increasing in number. The Danish part of the Wadden Sea is well protected, but still under pressure from changes in land use and recreational activities.